A number of people are saying rape can never be justified and murder can, so I'll give some examples of how rape can be justified.
1. A mad scientist will destroy the world with nuclear weapons unless you rape a particular person.
2. There are only two people left on earth and the human race will die out if one doesn't rape the other, regardless of which gender rapes the other.
I know those situations are ridiculous, but they're still there. It's not that easy to justify murder either. War doesn't justify murder. Just because your government gives you a gun and a uniform and sends you to a far off land doesn't mean it's okay for you to kill people. Self defense and any variation on the mad scientist situation (where in sacrificing one life will result in the saving of two or more lives) are really the only justifications for murder.
If you can kill unjustifiably in games, you can rape unjustifiably in games. Just because one is more socially acceptable than the other doesn't make it any less evil.
P.S. I don't know how anyone can compare yelling, "fire," in a crowded theatre can compare to pretending to rape anime girls in the privacy of your own home.
The "You usually kill the badguys in games" thing is also a crock. The majority of kills come from online multiplayer modes, in which two teams can't both be the badguys. And usually isn't always anyhow.
"Now, a fun game should always be easy to understand - you should be able to take one look at it and know what you have to do straight away. It should be so well constructed that you can tell at a glance what your goal is and, even if you don’t succeed, you’ll blame yourself rather than the game. Moreover, the people standing around watching the game have also got to be able to enjoy it." - Shiggy
